Whoa! You could strap a couple of lift bags on each arm to help out with the buoyancy! Do the words "saturation diving" come to mind?
Ron
Ron
Can you say Hernia!
- Thread starter Mario S Caner
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OP
I was just on the WKPP site and read a story that George Irvine wrote on diving to 18,000 in Wakulla and he makes a reference to 160cuft cylinders on his rebreather... here's a little peice of the article:
I was breathing helium, able to hover inches above the floor with three scooters, two drive botles, four safeties, and pick two clips up out of the silt without even puffing it while wearing a rebreather with twim 160's attached to it. I was remembering what Parker Turner told me, "It is the basics that keep you alive". I was thinking, "This is my basic lobster-catching buoyancy control at work". I was also thinking, "how am I doing this with a rebreather?". It is a good thing I do not teach it, as I have no idea how I do it. I thought about the first question on my rebreather exam, "What kills the most rebreather divers". I had answered, "Rule Number One", Jack Kellon got pissed , he said "Task loading". He told me Tom Mount had answered that question correctly, and he failed me and Bill Mee. We laughed until we cried, "Task Loading". Bill Mee and I are the only guys who ever failed the rebreather test. However, Mount and Jack were correct - turn your back on the rebreather snake and it bites you.
I've been looking around and still don't have anything on the 'beast'. Perhaps it was just a joke in a publication...
I was breathing helium, able to hover inches above the floor with three scooters, two drive botles, four safeties, and pick two clips up out of the silt without even puffing it while wearing a rebreather with twim 160's attached to it. I was remembering what Parker Turner told me, "It is the basics that keep you alive". I was thinking, "This is my basic lobster-catching buoyancy control at work". I was also thinking, "how am I doing this with a rebreather?". It is a good thing I do not teach it, as I have no idea how I do it. I thought about the first question on my rebreather exam, "What kills the most rebreather divers". I had answered, "Rule Number One", Jack Kellon got pissed , he said "Task loading". He told me Tom Mount had answered that question correctly, and he failed me and Bill Mee. We laughed until we cried, "Task Loading". Bill Mee and I are the only guys who ever failed the rebreather test. However, Mount and Jack were correct - turn your back on the rebreather snake and it bites you.
I've been looking around and still don't have anything on the 'beast'. Perhaps it was just a joke in a publication...
bio guy
Guest
For those metric people: 4400psi is approx 300 Bar
190 Cu Ft is (I think)about 25 Litres
(an 80 is a bit less than an standard european 10 Litre tank)
For those of you who try converting Cu Ft into Litres, don't, 'cos in europe tanks are sold by internal water capacity (ie how many litres of water it takes to fill the tank).
This was just for the imperially challenged.
Jon T
bdombrowski
Contributor
They tout that their ball-buster 190 cu ft. tank gives you the capacity of a set of standard doubles. They also put a dual valve on it. I hope they aren't implying that one use this in place of a set of doubles. Doubles provide redundancy. This thing doesn't. If a burst disk goes... you're done.
The CF and Liter measurement of tanks are two entirely different things.
When using the CF rating, we are referring to how much gas (at 1ATM) is stuffed into the tank at it's rated pressure, whereas the Liter rating is how much interior volume the tank has (pressure isn't considered). There are about 28 liters to a cubic foot - An "80" CF tank (77.4CF at 3000psi or 200 bar) - holds about 2200 liters of breathable air at the surface when full, but the internal volume of the tank is about 11 liters.
The monster tank (if it exists) that holds 190CF at 4400 psi (that's 5320 liters at 300 bar) would have a "liter" size of about 18 liters. (5320/300).
All numbers are approximate, but I hope you see the point.
Rick
When using the CF rating, we are referring to how much gas (at 1ATM) is stuffed into the tank at it's rated pressure, whereas the Liter rating is how much interior volume the tank has (pressure isn't considered). There are about 28 liters to a cubic foot - An "80" CF tank (77.4CF at 3000psi or 200 bar) - holds about 2200 liters of breathable air at the surface when full, but the internal volume of the tank is about 11 liters.
The monster tank (if it exists) that holds 190CF at 4400 psi (that's 5320 liters at 300 bar) would have a "liter" size of about 18 liters. (5320/300).
All numbers are approximate, but I hope you see the point.
Rick
Rick,
That is exactly the calculation that I did, however, you put more of the maths in, and also came up with a more acurate answere I suspect.
I just did a rough calculation in my head, itr looks like you put some numbers down on paper. and worked it out more accurately.
If that is only an 18L tank, then it is not too big, and I have seen number of 300bar 18L tanks in the UK. Whilst not being common, they aren't rocking horse droppings either.
J
That is exactly the calculation that I did, however, you put more of the maths in, and also came up with a more acurate answere I suspect.
I just did a rough calculation in my head, itr looks like you put some numbers down on paper. and worked it out more accurately.
If that is only an 18L tank, then it is not too big, and I have seen number of 300bar 18L tanks in the UK. Whilst not being common, they aren't rocking horse droppings either.
J
Well I don't want to cause any controversy, however my Nitrox instructor gave a special class session on BEUCHAT tanks alone. According to him, BEUCHAT/HEISER tanks have been tentatively linked to a tech diving triple fatality( and these weren't even the 190's!!!). The bouyancy characteristics caused a bouyancy/task loading situation on an Extended Range(trimix?) dive class' check out dive. According to him, and its been a while since I heard the story, a class of four including an instructor went down on the Instructors new B/H 's(never tried out b4). Supposedly one student overweighted and upon reaching max depth somewhere in the 250' range, couldn't get neutral, this here supposedly triggered a chain of events which led to the end of the dive being called. Here however supposedly it took the remaining three divers, with their wings fully inflated and grasping the manifold to make the overwieghted diver positive. Here supposedly one student slipped off of the manifold and shot up like a rocket blowing numerous deco stops. This left three divers on the bottom. The surviving student descended and began his contingency deco, where he spotted the instructor ascending and then eventually descending once again never to be seen again.
The story is as close as to what was described to me as I could remember. I will try to locate my instructor via e-mail in order try and substantiate this, thus not be left spreading rumors, rather than safety consciousness. I hope this doesn't offend. Just trying to pass along some knowledge from a man(Nitrox Instructor) who I respect very much. If anyone is familiar with the incident please feel free to correct me.
The story is as close as to what was described to me as I could remember. I will try to locate my instructor via e-mail in order try and substantiate this, thus not be left spreading rumors, rather than safety consciousness. I hope this doesn't offend. Just trying to pass along some knowledge from a man(Nitrox Instructor) who I respect very much. If anyone is familiar with the incident please feel free to correct me.
very simple fact - whatever the make of tanks, the CHANGE of buoyancy is ONLY dependant upon the AIR in the tank THAT YOU USE.
If you are neutral at the start, the only buoyancy change is that from the air you use.
If you use all your air, you become more positive. as the tanks now weigh less.
Note THIS is the CHANGE in buoyancy DURING a dive. Different materials will require different INITIAL weightings.
Put even more simply - air weighs something. as you use it, you lose that weight.
This accident sounds like somebody screwed up in their preparations, it doesn't sound like being dependant upon the tank type. - it is possible that he got his weight wrong so that as he lost buoyancy from his suit he was overweighted. Most divers that go deep that I know wear a dry suit even in relatively warm water to overcome this, as they can always add more air to their suit to maintain buoyancy.
Jon T
If you are neutral at the start, the only buoyancy change is that from the air you use.
If you use all your air, you become more positive. as the tanks now weigh less.
Note THIS is the CHANGE in buoyancy DURING a dive. Different materials will require different INITIAL weightings.
Put even more simply - air weighs something. as you use it, you lose that weight.
This accident sounds like somebody screwed up in their preparations, it doesn't sound like being dependant upon the tank type. - it is possible that he got his weight wrong so that as he lost buoyancy from his suit he was overweighted. Most divers that go deep that I know wear a dry suit even in relatively warm water to overcome this, as they can always add more air to their suit to maintain buoyancy.
Jon T
